The Uintatheriidae is a family of extinct mammals that includes Uintatherium. They belong to the order Dinocerata, one of several extinct orders of primitive mammals that are sometimes united in the Condylarthra.

Uintatheres were the largest land animals of their time, surviving from the late Paleocene into the Uintan Epoch of the Middle Eocene.[1] They were heavy animals, with thick legs, massive bones, broad feet, and tiny brains. The most distinctive feature of the great majority of species, however, was the presence of multiple blunt "horns", perhaps similar to the ossicones of modern giraffes, and the presence of large, sabre-like canine teeth. They were eventually replaced as large browsing animals by the brontotheres.[2]